This is a set of winders for the 3D printed terraPin pinhole cameras and the original P6X6. All these cameras are freely available for download at Thingiverse:
The winder assembly is notoriously weak when printed via FDM machines. These winders can be purchased in flexible nylon or stainless. The flexible nylon is plenty strong for most purposes, but in steel they will be indestructable. These winders have 1/4 inch shafts and are designed for control knobs typically used for electronics or appliance applications, available at Radio Shack, Fry's Electronics and many other sources. You may be able to remove indicator marks from your knob with acetone.
To keep costs down, the parts are connected. You will need to cut the sprue connecting the two parts. Trivial for plastic, steel will require a dremel or hacksaw and some finishing.